Current networks are comprised of elements built on a forward and forget paradigm with information about the network scattered across many network devices. Further the number of IP addresses is insufficient to provide a unique address to every piece of equipment on the network. As a result of the lack of sufficient IP addresses, and many enterprise networks choosing to use the private address space, many networks have private IP addresses that overlap with private addresses in other networks. In addition to use of private address space many entities need to secure their networks even while those networks use network infrastructure provided by others.
Tunneled traffic networks (“TTNs”) such as virtual private networks (“VPNs”) and virtual local area networks (“VLANs”), as well as networks using tunneling protocols such as multi-protocol label switching (“MPLS”), IPSec, L2TP, and asynchronous transfer protocol (“ATM”), were developed to allow companies with multiple physical locations to create a secure, single enterprise network that is transparent to the user. This is accomplished by the enterprise turning over much of the network infrastructure to carriers, such as MCI, AT&T, Southwestern Bell, etc., who connect the remote locations across their own publicly addressed private networks.
To make a TTN (reference to TTNs will hereinafter imply a reference to any network structure using tunneling, including, but not limited to, those listed above) work since there can be overlapping IP addresses used among the different TTNs being hosted by the carrier or even at the individual physical locations, information identifying the particular TTN being used must be added to the layer three information inside the packet which includes the source address information.
These TTNs make it impossible for most existing network equipment to route between them because of the overlapping addresses and the lack of knowledge about the characteristics of each of the TTNs in the network equipment.
Accordingly, what is needed is a method and device for creating virtual routing domains in IP networks.